perf: remove argument reassignments in View

History.md

@@ -66,6 +66,7 @@ unreleased
     - perf: reduce try block size
     - perf: remove bitwise operations
   * perf: enable strict mode
+  * perf: remove argument reassignments in `View`
   * perf: use saved reference to `http.STATUS_CODES`
 
 4.12.4 / 2015-05-17

lib/view.js

@@ -10,6 +10,7 @@
 
 /**
  * Module dependencies.
+ * @private
  */
 
 var debug = require('debug')('express:view');
@@ -29,7 +30,8 @@ var join = path.join;
 var resolve = path.resolve;
 
 /**
- * Expose `View`.
+ * Module exports.
+ * @public
  */
 
 module.exports = View;
@@ -43,30 +45,51 @@ module.exports = View;
  *   - `engines` template engine require() cache
  *   - `root` root path for view lookup
  *
- * @param {String} name
- * @param {Object} options
- * @api private
+ * @param {string} name
+ * @param {object} options
+ * @public
  */
 
 function View(name, options) {
-  options = options || {};
+  var opts = options || {};
+
+  this.defaultEngine = opts.defaultEngine;
+  this.ext = extname(name);
   this.name = name;
-  this.root = options.root;
-  var engines = options.engines;
-  this.defaultEngine = options.defaultEngine;
-  var ext = this.ext = extname(name);
-  if (!ext && !this.defaultEngine) throw new Error('No default engine was specified and no extension was provided.');
-  if (!ext) name += (ext = this.ext = ('.' != this.defaultEngine[0] ? '.' : '') + this.defaultEngine);
-  this.engine = engines[ext] || (engines[ext] = require(ext.slice(1)).__express);
-  this.path = this.lookup(name);
+  this.root = opts.root;
+
+  if (!this.ext && !this.defaultEngine) {
+    throw new Error('No default engine was specified and no extension was provided.');
+  }
+
+  var fileName = name;
+
+  if (!this.ext) {
+    // get extension from default engine name
+    this.ext = this.defaultEngine[0] !== '.'
+      ? '.' + this.defaultEngine
+      : this.defaultEngine;
+
+    fileName += this.ext;
+  }
+
+  if (!opts.engines[this.ext]) {
+    // load engine
+    opts.engines[this.ext] = require(this.ext.substr(1)).__express;
+  }
+
+  // store loaded engine
+  this.engine = opts.engines[this.ext];
+
+  // lookup path
+  this.path = this.lookup(fileName);
 }
 
 /**
  * Lookup view by the given `name`
  *
- * @param {String} name
- * @return {String}
- * @api private
+ * @param {string} name
+ * @private
  */
 
 View.prototype.lookup = function lookup(name) {
@@ -91,16 +114,16 @@ View.prototype.lookup = function lookup(name) {
 };
 
 /**
- * Render with the given `options` and callback `fn(err, str)`.
+ * Render with the given options.
  *
- * @param {Object} options
- * @param {Function} fn
- * @api private
+ * @param {object} options
+ * @param {function} callback
+ * @private
  */
 
-View.prototype.render = function render(options, fn) {
+View.prototype.render = function render(options, callback) {
   debug('render "%s"', this.path);
-  this.engine(this.path, options, fn);
+  this.engine(this.path, options, callback);
 };
 
 /**
@@ -113,12 +136,10 @@ View.prototype.render = function render(options, fn) {
 
 View.prototype.resolve = function resolve(dir, file) {
   var ext = this.ext;
-  var path;
-  var stat;
 
   // <path>.<ext>
-  path = join(dir, file);
-  stat = tryStat(path);
+  var path = join(dir, file);
+  var stat = tryStat(path);
 
   if (stat && stat.isFile()) {
     return path;